The subject invention relates to a wall and/or ceiling polymer-based composite structural sheathing board that has a polymer material or predominantly polymer material core layer and to a wall and/or ceiling system of a building structure that includes a plurality of the polymer-based composite structural sheathing boards overlaying and secured to a structural wall and/or ceiling frame and forming a wall and/or ceiling sheathing layer over the structural frame.
In current building wall and ceiling systems, the sheathing layers of the wall and ceiling systems are typically formed of plywood boards, hardboards, particleboards, and/or gypsum boards. While these structural sheathing boards perform satisfactorily, the physical properties of these structural sheathing boards, such as but not limited to their weight, handleablity, cutablity, durability, flame spread rating, water absorption and/or fungus growth characteristics, etc. can present problems during the installation of the sheathing layer and over the anticipated service life of a wall and/or ceiling system. Accordingly, there has remained a need for improved wall and ceiling systems which utilize sheathing layers that are formed by structural sheathing boards that can be relatively light in weight, that are easy to handle, and that are easily cut at the job site to form the sheathing layer. There has also remained a need for improved wall and ceiling systems that include sheathing layers made of structural sheathing boards that are strong and durable, that absorb and retain very little moisture, that are fungus growth resistant, that are flame spread resistant, that have relatively good thermal and acoustical properties, and that have good bonding surfaces for bonding a nonstructural finish layer to an sheathing layer formed by the structural sheathing boards.